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zamba.pytorch.utils

Functions

build_multilayer_perceptron(input_size: int, hidden_layer_sizes: Optional[Tuple[int]], output_size: int, activation: Optional[torch.nn.Module] = torch.nn.ReLU, dropout: Optional[float] = None, output_dropout: Optional[float] = None, output_activation: Optional[torch.nn.Module] = None) -> torch.nn.Sequential

Builds a multilayer perceptron.

Parameters:

Name Type Description Default
input_size int

Size of first input layer.

required
hidden_layer_sizes tuple of int

If provided, size of hidden layers.

required
output_size int

Size of the last output layer.

required
activation torch.nn.Module

Activation layer between each pair of layers.

torch.nn.ReLU
dropout float

If provided, insert dropout layers with the following dropout rate in between each pair of layers.

None
output_dropout float

If provided, insert a dropout layer with the following dropout rate before the output.

None
output_activation torch.nn.Module

Activation layer after the final layer.

None

Returns:

Type Description
torch.nn.Sequential

torch.nn.Sequential

Source code in zamba/pytorch/utils.py
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def build_multilayer_perceptron(
    input_size: int,
    hidden_layer_sizes: Optional[Tuple[int]],
    output_size: int,
    activation: Optional[torch.nn.Module] = torch.nn.ReLU,
    dropout: Optional[float] = None,
    output_dropout: Optional[float] = None,
    output_activation: Optional[torch.nn.Module] = None,
) -> torch.nn.Sequential:
    """Builds a multilayer perceptron.

    Args:
        input_size (int): Size of first input layer.
        hidden_layer_sizes (tuple of int, optional): If provided, size of hidden layers.
        output_size (int): Size of the last output layer.
        activation (torch.nn.Module, optional): Activation layer between each pair of layers.
        dropout (float, optional): If provided, insert dropout layers with the following dropout
            rate in between each pair of layers.
        output_dropout (float, optional): If provided, insert a dropout layer with the following
            dropout rate before the output.
        output_activation (torch.nn.Module, optional): Activation layer after the final layer.
    Returns:
        torch.nn.Sequential
    """
    if (hidden_layer_sizes is None) or len(hidden_layer_sizes) == 0:
        return torch.nn.Linear(input_size, output_size)

    layers = [torch.nn.Linear(input_size, hidden_layer_sizes[0])]
    if activation is not None:
        layers.append(activation())

    if (dropout is not None) and (dropout > 0):
        layers.append(torch.nn.Dropout(dropout))

    for in_size, out_size in zip(hidden_layer_sizes[:-1], hidden_layer_sizes[1:]):
        layers.append(torch.nn.Linear(in_size, out_size))
        if activation is not None:
            layers.append(activation())

        if (dropout is not None) and (dropout > 0):
            layers.append(torch.nn.Dropout(dropout))

    layers.append(torch.nn.Linear(hidden_layer_sizes[-1], output_size))

    if (output_dropout is not None) and (output_dropout > 0):
        layers.append(torch.nn.Dropout(dropout))

    if output_activation is not None:
        layers.append(output_activation())

    return torch.nn.Sequential(*layers)